1. Field of the Invention
The present invention is concerned with a freezer/refrigerator car for transporting foods in a frozen or refrigerated state.
2. Description of the Prior Art
In recent years, freezer/refrigerator cars have been widely used for transporting foods in a frozen or refrigerated state. The freezer/refrigerator cars of this type have been provided with a freezer/refrigerator having a carry-in/out opening at the rear end thereof for carrying goods in and out of the car, and a door for opening and closing the carry-in/out opening. In these freezer/refrigerator cars, when the door is opened for carrying goods in or out of the car, the cold air in the freezer/refrigerator flows out through the carry-in/out opening while the external air flows into the freezer/refrigerator. As a means for intercepting the flow in/out of the cold air and the external air, there has been employed an air curtain. The air curtain is generally of a system in which the air is blown downward from the upper side of the carry-in/out opening to form an air layer in the carry-in/out opening. According to the system in which the air is blown downward from the upper side of the carry-in/out opening, however, the cold air is blown out rearward along the ceiling surface from a cooling unit installed at a front upper end of the freezer/refrigerator and most of the cold air is utilized as an air curtain. Therefore, since it is difficult to prevent the cold air forming the air curtain further from flowing out of the freezer/refrigerator, there is a problem that the loss of the cold air is very large and the cooling effect is greatly lowered in the freezer/refrigerator.
In order to solve the above-mentioned problem of the air curtain system in which the air is blown out downward from the upper side of the carry-in/out opening, Japanese Laid-open Utility Model Publication (Kokai) No. 183639/1985 discloses a freezer car equipped with an air curtain system in which the air is blown out from the one side of the carry-in/out opening toward the other side to form a layer of air stream in the transverse direction across the opening of the carry-in/out opening. In this freezer car, an air curtain unit is disposed on one side of the carry-in/out opening of the freezer/refrigerator, and is constituted so as to blow the air out toward the other side from the air curtain unit across the carry-in/out opening.
In the freezer car disclosed in Japanese Laid-open Utility Model Publication (Kokai) No. 183639/1985, the air curtain unit is installed at a rear inner side of one side wall constituting the freezer/refrigerator. A door composed of a plurality of pieces of doors is arranged at the carry-in/out opening portion of the freezer/refrigerator. At the time of delivering goods, only some of the doors are opened to allow the goods to be carried in/out. At the time of loading the goods into the freezer/refrigerator, however, the doors are all opened to carry out the loading operation. In opening all of the doors and carrying out the loading operation as described above, the air curtain unit disposed at the rear inner side of one side wall of the freezer/refrigerator protrudes toward the carry-in/out opening to hinder the loading operation.
An object of the present invention is to provide a freezer/refrigerator car having an air curtain unit at a carry-in/out opening formed at a rear end of a freezer/refrigerator to blow the air out from the one side toward the other side, the air curtain unit being so disposed as will not to hinder the loading operation that is carried out upon leaving the doors open.
In order to accomplish the above-mentioned object according to the present invention, there is provided a freezer/refrigerator car equipped with a freezer/refrigerator that has a bottom wall, a ceiling wall, a front wall, both side walls and a carry-in/out opening formed at a rear end thereof for carrying the goods in and out, and is provided with a door mechanism for opening and closing the carry-in/out opening, wherein the door mechanism comprises a first door pivotably mounted on the one side wall of the freezer/refrigerator, a second door pivotably mounted on the other side wall of the freezer/refrigerator, and a third door pivotably mounted on the other side of the second door, and an air curtain unit is disposed on the inside surface of the first door and blows out the air toward the other side wall across the carry-in/out opening in a state where the first door is closed.